Research On Roadways Supporting Of Axis 10 Coal Seam On +400m Level Under Compound Roof In Da' An Shan Coal Mine

The roadways of Dong Yi working face on +400m level in Da'an Shan Coal Mine are located under the condition of high stress and compound roof, it is very difficult to support the roadways. Aiming at solving the supporting problem, the coupling support scheme of bolt-mesh-cable is put forward. Finally it shows that the scheme has good supporting effect, controlling the deformation and failure of roadway effectively.The physical mechanical parameters of coal, roof and floor strata are measured through experiment, using the hollow inclusion stress measuring instrument to measure the distribution laws of stress on +400m level, to provide basic parameters for simulation research. The failure laws of roadways under the condition of high stress and compound roof is studied by theoretical analysis, the roof experiencing slippage, separation and caving process. Using the software FLAC3D to study the changing laws of displacement and stress when the structure of compound roof is changing, it is found that when the distance of axis 10coal seam form roadway is small, the deformation and stress concentration of roadway is serious. The function of bolt and anchor cable is analyzed by theoretical analysis under high stress and compound roof. To undertake supporting design when axis 10coal seam is 1m away from roadway, composite beam theory is used to calculate the bolt parameters and the suspension theory is used to calculate the anchor cable parameters. According to the geological situation, support schemes of cable+long anchor and short anchor+long anchor are put forward, analyzing the displacement and stress concentration by numerical simulation. The results show that the deformation and destruction of surrounding rock can be controlled well.Based on geological conditions, support scheme of bolt+long anchor is used, monitoring the displacement of surrounding rock and anchor force at four different locations, it is found that deformation tends to converge after 25 days, and basically reach the stable state, the anchoring force can meet the support design requirements, but doesn't reach breaking load. The results of displacement and anchoring force show that support scheme is safe and feasible. The research results have important significance to safety production in Da'an Shan Coal Mine and other coal mines with similar geological conditions.